Learn to code by writing code.
Real code in your browser, checked by tests the moment you press Run.
JavaScriptPrinting
Instructions
Print your age with
console.log(). It's a number, so write it without quotes.On the next line, print your name. It's text, so put it in quotes.
Tab inserts spaces. To leave the editor, press Escape, then Tab.
Console
Checked the moment you run it
Read a short explanation, write the code yourself and press Run. The tests check it right away, and if one fails, you get a free hint, never the answer.
A habit, not a marathon
Pick a goal of 1, 3, 5 or 10 exercises a day and build a streak, one day at a time. Every exercise you solve for the first time earns XP.
Exercises a day
From first lesson to final project
Lessons build on each other, a small project every few lessons puts them to use, and a final project rounds off the course.
It all runs in your browser
Python, C, SQL and the rest run right on the page, with nothing to install. Every course is in Czech and English.
Pick a path or a language
1,236 exercises in Czech and English. Every course has small projects along the way and a final project at the end.
Become a web developer
From your first line of HTML to a React app of your own: HTML, CSS, JavaScript, Tailwind and React, in the right order, with one website that grows along the way.
5 courses · 4 projects · 537 exercises
Algorithmic Thinking6 lessons · 29 exercises
HTML8 lessons · 60 exercises
CSS12 lessons · 89 exercises
Tailwind CSS13 lessons · 93 exercises- JavaScript17 lessons · 142 exercises
React15 lessons · 108 exercises
Vue15 lessons · 104 exercises
TypeScript13 lessons · 99 exercises
Python9 lessons · 85 exercises
C13 lessons · 116 exercises
C++10 lessons · 87 exercises
Lua15 lessons · 118 exercises
SQL13 lessons · 106 exercises- Not sure where to start?Answer a question or two and we'll suggest where to start.
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Free
- The first lesson of every course
- 119 exercises
- A hint when a test fails, 50 a day
- All you need is an account
The whole catalog
Pro
- All 13 courses and 1,236 exercises
- The AI assistant for questions about your code
- 50% cheaper with yearly billing
- Cancel any time
Your whole class in one place
Every student codes in their own account, and you can follow the whole class.
- Teacher and student accounts
- Every student's progress in one place
- Sign-in with your school's Microsoft account
The next line is yours.
Start with the first lesson of any course. It's free.